Process of coating iron and steel shapes with other metals



-shapes, such, for example Patented Mar. 10, 1925.

, UNITED STATE PATENT ,oFFIcE.

SAMUEL Peacock; on wnEELnre, wns'r VIRGINIA, as srer'ron mo WHEEIQING STEEL a IRON COMPANY, or WHEELING, wEs'r vmsrma, A OORPQRATION or wrs'r VIRGINIA.

rRocEss-or comme IRON AND swam. smras wr'rn ornnn mans No Drawing.

To all whom it may co'naem:

Be ,it known that I, SAMUEL PEACOGK, a citizen of the United States, residin at Wheeling, in the county of Ohio and tate 5 of West Virginia, have invented certain new and useful Improvements in Processes of Coating Iron and Steel Shapes .with Other Metals; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

'This invention relates to a process of coating iron or steel shapes in generalwith I 5 other metals and alloys and has for its object to improve as well as to lessen the cost of the processes heretofore proposed.

7 With. these and other" objects in view the invention consists-in the novel steps and combinations of steps constituting the process, all as will more fully hereinafter I disclosed and particularly pointed out in -the claims.

' It is well known that steel and iron s plates and other iron and steel objects, have been heretofore coated with tin, copper, and other metals by various electrolytic processes, but

metal or alloy'is too rapidly deposited it will be more'orless pulverulent, porous or fluffy in character, and therefore non-adherent and worthless for protective purposes, On the other hand, it is equally well known that the relatively slow and tedious process of making a coherent, firm, tenacious, andvs'atisfactory coating by processes now available is relatively so costly that iron and steel coated articles are not as freely' used as they would be if this cost could "be reduced.

The required time and fine adjustments of'the various factors of the prior roc'esses contribute largely to the items 0 cost of coating one metal with another, which it is the object of this invention to reduce.

In car g out this invention for the deposition 0 tin on steel, for example, I may provide coating solutions of stannous chlo- 50. ride and ammonium alum of the usual conoentrations employed in electroplating processes, or in chemically depositing processes,

" or I may somewhat increase their concen- Application filed at, 7,

it is =also well known that if the coating.

1922. Serial No. 566,657.

cost of removing this ever-present blackoxide coating in the making of so called tin plate constitutes a large item of the total cost of the process. Further, instead of causing the deposition of the t i n coating to be gradually efl'ected as was necessary in the prior procedures to obtain a firmand coherent deposit, I cause the coating to. be deposited relatively very rapidly, so that it appears in a more or less pulverulent, po-

rous, and non' adhering form. This formin the prior procedureswould not be suitable at all for the purpose in hand, but in this process it is highly suitable in that it serves to get the requisite amount of tin in contact with the steel in a minimum of time, and without having to adjust such factors as purity of solution, temperature of deposition, concentration, etc., all of which areannoying and cost money in large scale operations. But, of course, I

maintain the strength of the solution fairly constant by the usual stirring means and by the presence ofundissolved' tin, or tin 'salts in'the solution.

Having thus secured a porous coating of tin on theoxidized surface of a sheet of steel, for example, in a relatively very short time, I nextiwash and dry the coated sheet in the usual manner, when it will be found ,to possess a dull surfaced coating which is non-crystalline, orous, and easily -rubbed or scratched ofi.

together and made to adhere to the surface of the steel sheet or plate at a temperature which is say 200 F. below the melting point of the tin itself. Accordingly, I next. suitably'heat up the coated steel plate to about 250 F. The oxygen which was resent in the ferro-ferric oxide coating 0 the have foundthat the par- ,ticles of this porous coating may be fritt d steel sheet will be found to have been used "up oxidizing a portion of the tin in the solution, so that the remaining tin will nowv enter the non-oxidized, or reduced surface of the steel sheet, or plate, and form a firm, tenacious and exceedingly coherent protecting film of tin of the highest quality. The finished product, if it is to be used for. tin cans is next polished or further treated as in the prior-processes.

In case copper is to be deposited on steel sheets, or other iron or steel shapes, substantially the same procedure is carried out except a solution of copper sulphate is preferably employed, and the porous coating is fritted together at-a temperature of, say, 300 C. below the meltin point of the copper. In the case of nicke ,this temperature is about 400 C. below the. melting point of the nickel.

Alloys are deposited in the same general way as that outlined for tin. That is, a

' porous relatively non-adherent coating of the alloy on.the steel sheet is produced in the manner well known, when itis fritted toether at a temperature well below its meltmg point, but sufficiently high to cause the constituents oi the coating present to remove any remaining oxide on the steel surface to be coated, to the end that the coating material will deposit on a clean surface before said surface has a chance to be reoxidized. 4

The heatin process should be carried out in a non-oxi izing atmosphere. Wherever the term metal or metals occur in the claims, and referto the coating material it is to be understood that: metal alloys are to be included. 5

It is obvious that those skilled in the art may vary the details of the process, without departing from the spirit of the invention, and therefore I do not wish -to "be limited to the foregoing disclosure except as may be required by the claims.

What is clalmed is: I 1. The process of coatin iron and steel shapes with other metals w ich consists in covering the surfaces to be-protected when in an oxidized condition with a porous and relatively non-adherentdeposit of the coating metal from a solution; and by the aid of heat converting said deposit into a partially oxidized non-porous and adherent protecting film on said surfaces, substantially as described. 7

2. Theprocess of coating iron and steel shapeswith other metals which consists in covering the surfacesto be protected when in an oxidizedcondition with. a porous and relatively non-adherent deposit of the coating metal from a solution containing an ad'- dition agent; and by the aid of heat converting said deposit into a partially oxidized non-porous and adherent protecting film on said surfaces, substantially as described.

3. The process of coating the surfaces of iron and steel shapes with another metal which consists in coverin said surfaces when in an oxidized condition with a solution of the coatin metal; depositing out said metal onto sai surfaces in a relatively porous and non-adherent film; and raising the temperature to a point sutficient to frit together the particles of said coating and to provide a relatively non-porous adherent protecting film on the objects coated, substantially as described.

4. The process of coating the surfaces of I iron and steel shapes with another metal which consists in covering said surfaces when in an oxidized condition with a'solution of the coating metal; depositing out said -metal onto said surfaces in a relatively porous and non-adherent filmand raising the temperature in a non-oxidizin atmosphere .to a 'pointsuificient to partially frit together the particles of said coating andto provide a relatively non-porous adherent protecting film on the objects coated, sub- 'stantially as described.

In testimony whereof I aifix my signature.

SAMUEL PEACOCK. 

